1. Field of the Invention
The present invention relates to a chloroprene rubber composition, a vulcanizate thereof, and molding using them. More specifically, the present invention relates to a chloroprene rubber composition used for rubber moldings such as a wiper blade and a vibration isolator.
2. Description of the Related Art
Chloroprene rubber is excellent in heat resistance, weather resistance, ozone resistance, chemical resistance, and other properties and has been used in wide variety of fields such as general industrial rubber products, automobile parts, and adhesives. Such a chloroprene rubber molded piece is typically produced by molding a chloroprene rubber composition including a chloroprene rubber in combination with a vulcanizing agent, a vulcanization accelerator, a filler, and other components into a predetermined shape and then vulcanization.
Examples of the vulcanization accelerator used for such a production process include a thiourea vulcanization accelerator, a thiazole vulcanization accelerator, a thiuram vulcanization accelerator, and a guanidine vulcanization accelerator (for example, see Patent Document 1). For example, in a chloroprene rubber composition described in Patent Document 1, combination use of a thiourea vulcanization accelerator and a thiuram vulcanization accelerator intends to improve both scorch stability and permanent compression set characteristics.
Meanwhile, the chloroprene rubber is inferior in low temperature characteristics. To address the problem, chloroprene rubber compositions have been developed for improving low temperature resistivity (see Patent Documents 2 and 3). In addition, a high damping rubber composition has been developed (see Patent Document 4). The composition includes a natural rubber and a chloroprene rubber, and the natural rubber alone is vulcanized, thus improving damping characteristics.